Transdermal peptide with nuclear localization ability and use thereof

ABSTRACT

A transdermal peptide with a nuclear localization ability and having an amino acid sequence as shown in SEQ ID NO: 1 is disclosed. A fusion protein including a macromolecular protein with one end being linked to the transdermal peptide is also disclosed. The transdermal peptide can be used in the preparation of a medicament or a transdermal preparation for treating skin diseases. A medicament for treating a skin disease includes the transdermal peptide and a pharmaceutically acceptable excipient. The transdermal peptide enters the cells autonomously to locate in the nuclei, and can penetrate through the stratum corneum of the skin into cells in the dermis. The peptide is conveniently synthesized artificially and suitable for transdermal administration, and has a therapeutic potential via transdermal administration by carrying a drug for treating skin diseases.

This application is the Divisional Application of U.S. Ser. No.16/484,153, filed on Aug. 7, 2019, which is the National StageApplication of PCT/CN2017/105051, filed on Sep. 30, 2017, which claimspriority to Chinese Patent Application No.: CN 201710790765.3, filed onSep. 5, 2017, which is incorporated by reference for all purposes as iffully set forth herein.

FIELD OF THE INVENTION

The present invention relates to the field of biological technology, andmore particularly to a transdermal peptide with nuclear localizationability and use thereof.

DESCRIPTION OF THE RELATED ART

The skin is the largest organ in the human body. It covers the surfaceof the whole body, accounts for about 16% of the body weight, and has atotal area of up to 1.2 to 2 square meters. The skin consists of theepidermis layer, the dermis layer and the subcutaneous tissue, and isrich in blood vessels, nerves and various skin appendages, includinghair, hair follicles, sweat glands, and sebaceous glands. It is thebody's first line of defense, preventing the tissues and internal organsfrom being attacked by external physical, chemical, and biologicalstimuli. In addition, the skin also has the functions of immune,stimulus perception, body temperature regulation, absorption, secretionand excretion. The stratum corneum is the outermost part of theepidermis and consists essentially of 10-20 layers of flat, dead cellswithout nuclei. When these cells fall off, the underlying cells in thebasal stratum are pushed up to form a new stratum corneum. The functionof the stratum corneum is to protect the skin physically, mechanically,chemically and biologically against damage from harmful substances andto maintain the function integrity by blocking the entry of mostmacromolecular substances. However, the barrier of the stratum corneumalso prevents the absorption, by the epidermis and the dermal tissue, ofexogenous nutrients and drugs supplied through the epidermis.

Transdermal penetration enhancers are one class of compounds which canaccelerate the penetration of external drugs through the skin, such aspyrrolidones, azones, terpenoids, esters of amino acids and the like.However, the existing transdermal penetration enhancing compounds have ashort duration of action, are susceptible to metabolization, have a poortransdermal effect, have skin toxicity at a high concentration, and havelittle effect on the transdermal penetration of biologicalmacromolecules such as proteins.

Because macromolecular proteins and polypeptide drugs are hydrophilicmacromolecules, they can hardly penetrate the lipophilic barrier of thestratum corneum of the skin. Even with the help of transdermalpenetration enhancers, protein molecules with a molecular weight ofgreater than 500 Da are difficult to penetrate through the stratumcorneum. Therefore, transdermal administration of biologically activemacromolecular proteins has not been solved for a long time. How toenable biological macromolecules with important value to be administeredthrough the epidermal route has become a difficult and hot topic ofresearch. Extensive research is performed on the transdermal penetrationof proteins mediated by physical methods, including ultrasonic method,electric shock, and microneedle, etc. However, because of the dependenceof the above methods on equipment, it is difficult to put them intolarge-scale applications.

The use of peptide-mediated transdermal penetration of proteins hasattracted wide attention in recent years. After finding a new peptidethat can mediate the transdermal penetration of macromolecules, it isexpected that relevant diseases can be treated by transdermaladministration by linking functional proteins, polypeptides andcompounds to the transdermal peptide. Therefore, it is of greatpractical significance to provide a transdermal peptide with a nuclearlocalization ability.

The nucleus is the largest and most important organelle in eukaryoticcells, the regulatory center of cell heredity and metabolism, and one ofthe most notable markers of eukaryotic cells distinguished fromprokaryotic cells. Both the cell membrane and the nuclear membrane areselectively permeable membranes, which provide a protection for thecells and cell nuclei, and also prevent the entry of functional cellsand nuclear protective molecules. Therefore, screening peptides that canmediate the entry of key molecules into the cell membrane and nuclearmembrane and be localized in the nucleus is of great significance fordelivering important molecules to protect the nucleus. However, thereare no reports of peptides with both nuclear localization andtransdermal penetration abilities.

SUMMARY OF THE INVENTION

In order to solve the above technical problems, an object of the presentinvention is to provide a transdermal peptide having a nuclearlocalization ability and use thereof. The transdermal peptide of thepresent invention can enter the cell autonomously and be located in thenucleus, and can penetrate through the stratum corneum of the skin intocells in the dermis. The peptide is conveniently synthesizedartificially and can be administered transdermally.

The present invention provides a transdermal peptide with a nuclearlocalization ability, which has an amino acid sequence as shown in SEQID NO: 1, and can enter the eukaryotic cells autonomously.

Preferably, the transdermal peptide is further linked to fluorescein.

Preferably, the fluorescein is fluorescein isothiocyanate (FITC),rhodamine or carboxyfluorescein (FAM).

Preferably, the eukaryotic cells are HaCaT cells, WS1 cells, TE-1 cells,Eca-109 cells, HeLa cells or primary skin cells.

The transdermal peptide with a nuclear localization ability has anisoelectric point of 10.92 and a molecular weight of 2465 Da.

The transdermal peptide enters eukaryotic cells in a dose-dependent andtime-dependent manner, and can successfully enter the cells at aconcentration of 0.1-10 μmol/L after 0.1-240 min.

The present invention further provides a fusion protein with a nuclearlocalization ability, which comprises a macromolecular protein, one endof which is linked to the above-described transdermal peptide (having anamino acid sequence as shown in SEQ ID NO: 1) with a nuclearlocalization ability.

Preferably, the transdermal peptide is further linked to fluorescein.

Preferably, the other end of the macromolecular protein is linked to afluorescent protein.

Preferably, the fluorescent protein is enhanced green fluorescentprotein (EGFP).

Preferably, the molecular weight of the macromolecular protein is 10-50KD.

Preferably, the macromolecular protein has an amino acid sequence asshown in SEQ ID NO: 2; or the macromolecular protein is human superoxidedismutase 1 (SOD1).

The present invention also discloses the use of the transdermal peptide(having an amino acid sequence as shown in SEQ ID NO: 1) with a nuclearlocalization ability in the preparation of a medicament or a transdermalpreparation for treating skin diseases.

Preferably, the skin disease is skin injury, and more preferably, theskin disease is radiation skin injury.

Preferably, the transdermal peptide is further linked to fluorescein.

The present invention also provides a medicament for treating a skindisease, comprising the transdermal peptide with a nuclear localizationability and a pharmaceutically acceptable excipient.

Preferably, the dosage form of the medicament for treating a skindisease is a water extract, a powder, a lotion, a tincture, an oilyagent, a cream, an ointment, a plaster or an aerosol.

By means of the above technical solution, the present invention has thefollowing advantages.

The transdermal peptide disclosed in the present invention has theability to localize into the nucleus after entering the cellautonomously on one hand; and has transdermal penetration ability andcan penetrate through the stratum corneum of the skin into the cells inthe dermis on the other hand. The short peptide has a small molecularweight, is convenient for artificial synthesis, and can be administeredthrough the epidermis, and has the potential to carry transdermaltherapeutic drugs for treating skin diseases.

After the transdermal peptide is fused with a macromolecular protein,the obtained fusion protein can enter the cells and be localized in thenuclei, indicating that the transdermal peptide of the present inventionhas the function of carrying the macromolecular protein linked theretoto enter the cells and being localized in the nuclei.

These and other objects and advantages of the present invention willbecome readily apparent to those skilled in the art upon reading thefollowing detailed description by referring to the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the detection results of abilities to enter HaCaT cells andlocalize in the nuclei of the transdermal peptide of the presentinvention and the control peptide after labeling with FITC;

FIG. 2 shows the detection results of abilities to enter WS1 cells andlocalize in the nuclei of the transdermal peptide of the presentinvention and the control peptide after labeling with FITC;

FIG. 3 shows the detection results of abilities to enter TE-1 cells andlocalize in the nuclei of the transdermal peptide of the presentinvention and the control peptide after labeling with FITC;

FIG. 4 shows the detection results of the dose and time dependence ofthe percentages of the transdermal peptide of the present inventionentering HaCaT cells after labeling with FITC;

FIG. 5 shows the test result of the fusion protein of the presentinvention entering HaCaT cells and being localized into the nuclei; and

FIG. 6 is a schematic view showing the results of the transdermalpenetration effect of the transdermal peptide of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention will be further illustrated in more detail with referenceto the accompanying drawings and embodiments. It is noted that, thefollowing embodiments only are intended for purposes of illustration,but are not intended to limit the scope of the present invention.

Example 1

The raw materials and reagents for the transdermal peptide with anuclear localization ability provided in the present invention arecommercially available.

A peptide having an N terminus labeled with FITC was synthesized by thefmoc method, which has an amino acid sequence as shown in SEQ ID NO: 1.The synthesized peptide was dissolved in a phosphate buffer (PBS,pH=7.4) to prepare a solution having a concentration of 500 μmol/L.HaCaT cells were cultured in vitro, and when the cells were grown to acell density of 50%, the polypeptide solution was added to the medium ata final concentration of 10 μmol/L. After 4 hrs, DAPI was added fornuclear staining for 30 min. The culture medium was discarded, the cellswere rinsed three times with PBS, and photographed under a confocalfluorescence microscope after the free fluorescent polypeptide wasremoved. For comparison, a control polypeptide as shown in SEQ ID NO: 3was synthesized using the above method, where the N-terminus of thecontrol polypeptide was also labeled with FITC. The fluorescenceintensity was tested by culturing the cells with the control polypeptideaccording to the above method. The results of comparison with theuntreated control cells are shown in FIG. 1. FIG. 1 shows that a greenfluorescent signal can be observed in the nuclei of the cells (thetreatment group with the target polypeptide) to which the peptide of thepresent invention is added, and there is no green fluorescence in thecells added with the irrelevant control polypeptide (the treatment groupwith the irrelevant polypeptide), indicating that the peptide of thepresent invention has a function of entering HaCaT cells.

Example 2

The transdermal peptide of the present invention and the controlpolypeptide were synthesized according to the method as described inExample 1, and the N-termini of both polypeptides were labeled withFITC. The human fibroblasts WS1 were cultured following the method asdescribed in Example 1, and when the cells were grown to a cell densityof 50%, the polypeptide solution or the control polypeptide solution wasadded to the medium at a final concentration of 10 μmol/L. After 4 hrs,DAPI was added for nuclear staining for 30 min. The culture medium wasdiscarded, the cells were rinsed three times with PBS, and photographedunder a confocal fluorescence microscope after the free fluorescentpolypeptide was removed. The results of comparison with the untreatedcontrol cells are shown in FIG. 2. FIG. 2 shows that a green fluorescentsignal can be observed in the nuclei of the cells (the treatment groupwith the target polypeptide) to which the peptide of the presentinvention is added, and there is no green fluorescence in the cellsadded with the irrelevant control polypeptide (the treatment group withthe irrelevant polypeptide), indicating that the peptide of the presentinvention has a function of entering WS1 cells.

Example 3

The transdermal peptide of the present invention and the controlpolypeptide were synthesized according to the method as described inExample 1, and the N-termini of both polypeptides were labeled withFITC. The TE-1 cells were cultured following the method as described inExample 1, and when the cells were grown to a cell density of 50%, thepolypeptide solution or the control polypeptide solution was added tothe medium at a final concentration of 10 μmol/L. After 4 hrs, DAPI wasadded for nuclear staining for 30 min. The culture medium was discarded,the cells were rinsed three times with PBS, and photographed under aconfocal fluorescence microscope after the free fluorescent polypeptidewas removed. The results of comparison with the untreated control cellsare shown in FIG. 3. FIG. 3 shows that a green fluorescent signal can beobserved in the nuclei of the cells (the treatment group with the targetpolypeptide) to which the peptide of the present invention is added, andthere is no green fluorescence in the cells added with the irrelevantcontrol polypeptide (the treatment group with the irrelevantpolypeptide), indicating that the peptide of the present invention has afunction of entering TE-1 cells.

Example 4

The transdermal peptide of the present invention was synthesizedaccording to the method as described in Example 1, and the N-terminal ofthe polypeptide was labeled with FITC. The HaCaT cells were cultured inmultiple petri dishes following the method as described in Example 1,and when the cells were grown to a cell density of 50%, the polypeptidesolution was added to the medium at a final concentration of 0 μmol/L, 3μmol/L, 6 μmon, and 10 μmol/L respectively. After 4 hrs, DAPI was addedfor nuclear staining for 30 min. The culture medium was discarded, thecells were rinsed three times with PBS, and photographed under aconfocal fluorescence microscope after the free fluorescent polypeptidewas removed.

Alternatively, after the cells were grown to a cell density of 50%, thepolypeptide solution was added to the medium at a final concentration of10 μmol/L, and after 0, 60, 120, and 240 min, DAPI was added for nuclearstaining for 30 min. The culture medium was discarded, the cells wererinsed three times with PBS, and photographed under a confocalfluorescence microscope after the free fluorescent polypeptide wasremoved. The results are shown in FIG. 4. The percentage of cells havingfluorescence signal in the nuclei of the cells to which the peptide ofthe present invention is added is dose-dependent (shown in FIG. 4A) andtime dependent (shown in FIG. 4B). As the dose of the polypeptideincreases and the time elapse, more polypeptide enters the cells.

Example 5

This example provides a fusion protein and the abilities of the fusionprotein to enter the cells and localize in the nuclei are detected. Thespecific method is as follows.

1. Construction of Gene of Coupled Protein Fused with Peptide withNuclear Localization and Transdermal Penetration Abilities

A peptide (having an amino acid sequence as shown in SEQ ID NO: 1) withnuclear localization and transdermal penetration abilities, and a fusionprotein of a protein as shown in SEQ ID NO: 2 with enhanced greenfluorescent protein (EGFP) were constructed. The gene encoding the aboveprotein is in the middle, the EGFP encoding gene is located at the Nterminus, and the gene encoding the peptide with nuclear localizationand transdermal penetration abilities is located at the C terminus. Thenucleic acid was designed and synthesized according to the sequence ofthe polypeptide and the protein, and then inserted into the pET-28avector (Novagen, USA) to construct pET-28a-EGFP-pep, and the insertedsequence was sequenced and identified to be correct.

2. Expression of Fusion Gene in E. coli

E. coli BL21 (DE3) was transformed with the constructed vectorpET-28a-EGFP-pep. When the bacterial solution was grown to an OD600 of0.6, IPTG (final concentration: 1 mmol/L) was added to perform inductionat 30° C. for 10 hrs.

3. Purification of Fusion Protein

The bacteria solution induced to expression was treated for 1 hr byadding a lysozyme, ultrasonically homogenized, and centrifuged at 12,000rpm for 30 minutes at 4° C. The expression product was dissolved in thesupernatant. After centrifugation, the supernatant was transferred to a10 mL Eppendorf tube, and Ni-NTA (Novagen, USA) was added, and shaken at50 rpm for 2 h at 4° C. The above mixture was transferred to achromatographic column, and 4 ml of Wash Buffer (containing PBS and 0.1M imidazole) was added to wash the chromatographic column when theliquid was running out. When the liquid was almost completely flowedthrough, 300 μL of an eluate (containing PBS and 0.4 M imidazole) wasadded, and the efflux protein peak was collected under a nucleicacid/protein detector. The purified liquid was subjected to SDS-PAGEanalysis and the molecular weight was about 50 KD, which was consistentwith the calculated value. Through the above method, a fusion proteinwith a purity of over 90% can be obtained.

4. Detection of Abilities to Enter Cells and Localize in Nuclei ofFusion Protein

HaCaT cells were cultured in vitro, and when the cells were grown to acell density of 50%, the purified fusion protein was added to the mediumat a final concentration of 10 μmol/L. After 4 hrs, DAPI was added fornuclear staining for 30 min. The cells were rinsed three times with PBS,and photographed under a confocal fluorescence microscope after the freefusion protein was removed. The results show that after adding thepeptide of the present invention fused to the fusion protein of thepolypeptide and EGFP, a green fluorescent signal is observed in thenuclei of HaCaT cells (FIG. 5), indicating that the peptide has thefunction of carrying a macromolecular protein molecule attached theretoto enter the cells and localize in the nuclei.

Example 6

In this example, the transdermal penetration effect of the peptide wasdetected through the following specific method.

The experiments were performed using 8-week old SD rats (body weight 250g). The back of SD rats was shaved, and the FITC-labeled peptide andcontrol peptide prepared in Example 1 were each dissolved in a phosphatebuffer (PBS, pH=7.4) to prepare a solution having a concentration of 500μmol/L. The SD rats were divided into three groups, including: 1) acontrol group, in which no polypeptide solution was applied on the back;2) a control group, in which the peptide as shown in SEQ ID NO: 3 wasapplied on the dorsal epidermis of rats; and 3) a treatment group, inwhich the peptide as shown in SEQ ID NO: 1 was applied on the back skinof rats. The rats in Groups 2) and 3) were each applied with 50 μL ofthe polypeptide solution. After three hours, the polypeptide in theapplied area was washed off; the SD rats were sacrificed, and the skinapplied with the polypeptide was taken, frozen, sectioned, and thenobserved under a fluorescence microscope. The test results show thatthere is no green fluorescence in the dermal tissue of the skin of thecontrol group (untreated rat skin) and the control peptide group(control group applied with irrelevant polypeptide) (the arrow in FIG. 6indicates the stratum corneum with autofluorescence). In the skinsection of rats coated with the peptide of the present invention (thepolypeptide of interest), a fluorescent signal (the fluorescent signalshown in the ellipse in FIG. 6) is clearly observed in the skinappendages of the dermis, indicating that the peptide can transdermallypenetrate into the dermal tissue.

Example 7

The transdermal peptide (with an amino acid sequence as shown in SEQ IDNO: 1) of the present invention was used in the preparation of amedicament for treating skin diseases, and was prepared as a waterextract after adding a conventional excipient.

The transdermal peptide (with an amino acid sequence as shown in SEQ IDNO: 1) of the present invention was fused with human superoxidedismutase 1 (SOD1), expressed, and then applied once a day to the micefrom which the epidermis on the back was removed. The control group wasapplied with SOD1 not linked to the polypeptide of the presentinvention. The results show that after three days, the wounds of therats in the experimental group are reduced by 38% compared with thecontrol group, indicating that the peptide of the present inventionmediates the entry of SOD1 into cells to effectively treat skin wounds.

Example 8

The transdermal peptide (with an amino acid sequence as shown in SEQ IDNO: 1) of the present invention was used in the preparation of amedicament for treating skin diseases, and was prepared as a powderafter adding a conventional excipient.

Example 9

The transdermal peptide (with an amino acid sequence as shown in SEQ IDNO: 1) of the present invention was used in the preparation of amedicament for treating skin diseases, and was prepared as an oily agentafter adding a conventional excipient.

Example 10

The transdermal peptide (with an amino acid sequence as shown in SEQ IDNO: 1) of the present invention was used in the preparation of amedicament for treating skin diseases, and was prepared as a cream afteradding a conventional excipient.

Example 11

The transdermal peptide (with an amino acid sequence as shown in SEQ IDNO: 1) of the present invention was used in the preparation of amedicament for treating skin diseases, and was prepared as an ointmentafter adding a conventional excipient.

Example 12

The transdermal peptide (with an amino acid sequence as shown in SEQ IDNO: 1) of the present invention was used in the preparation of amedicament for treating skin diseases, and was prepared as a plasterafter adding a conventional excipient.

Example 13

The transdermal peptide (with an amino acid sequence as shown in SEQ IDNO: 1) of the present invention was used in the preparation of amedicament for treating skin diseases, and was prepared as an aerosolafter adding a conventional excipient.

The above description is only preferred embodiments of the presentinvention and not intended to limit the present invention, it should benoted that those of ordinary skill in the art can further make variousmodifications and variations without departing from the technicalprinciples of the present invention, and these modifications andvariations also should be considered to be within the scope ofprotection of the present invention.

What is claimed is:
 1. A fusion protein with a nuclear localization ability, comprising a macromolecular protein, one end of which is linked to an isolated transdermal peptide with a nuclear localization ability, having an amino acid sequence as shown in SEQ ID NO: 1 and being linked to a fluorescein, wherein the transdermal peptide enters the eukaryotic cells autonomously.
 2. The fusion protein with a nuclear localization ability according to claim 1, wherein the other end of the macromolecular protein is linked to a fluorescent protein.
 3. The fusion protein with a nuclear localization ability according to claim 1, wherein the macromolecular protein has a molecular weight of 10-50 KD.
 4. The fusion protein with a nuclear localization ability according to claim 1, wherein the macromolecular protein has an amino acid sequence as shown in SEQ ID NO: 2, and the macromolecular protein is human superoxide dismutase. 